National occupational-health operator Concentra runs its Hillcrest medical center at 3930 Fourth Avenue, Suite 200 inside the 92103 medical corridor. The clinic handles workers' compensation injuries, DOT physicals, pre-employment drug screens, and walk-in treatment for sprains, fractures, and respiratory illness, giving San Diego employers an alternative to routing minor work injuries through the after-hours pipeline at Perlman Clinic San Diego. Board-certified physicians, nurse practitioners, physician assistants, and certified physical therapists staff the location, which is built with multiple exam rooms and a dedicated on-site physical therapy area for return-to-work rehab. Concentra Telemed connects employees with clinicians for minor work injuries without a site visit, and complex hand and upper-extremity cases that exceed on-site PT capacity are routinely co-managed with specialists at Advanced Hand Therapy. Drug-screen chain of custody for DOT-regulated employers -- pre-employment, random, post-accident, and reasonable-suspicion testing under 49 CFR Part 40 -- is the most procedurally demanding service line and drives most employer account activity at the Hillcrest center.